1. Field of the Invention
This invention relates generally to mechanisms for automatic preparation and processing of mailable articles, and more particularly to mailable article processing devices for closing of flaps of envelopes during high-speed automatic handling of envelopes.
2. Prior Art and Other Considerations
Insertion machines for preparation and processing of mailable articles by automatically inserting varous inserts into envelopes often include devices for closing of flaps and sealing of envelopes.
For instance, U.S. Pat. No. 4,932,188 to Krasuski et al. discloses apparatus for closing envelopes, wherein envelopes 5 travel along a path (in a first direction) with the flap trailing (gummed face down) through a moistening mechanism that is moved into contact with the gummed flap surface (FIG. 2B). Once the flap has exited from the moistening mechanism, the envelope is stopped and a fold-and-closing roller arrangement is moved into position onto the flap so that the flap is deflected downwardly (FIG. 2C). Thereafter, envelope 5 is moved in the reverse direction with the flap being folded onto the envelope and pressed thereon by and between presser rollers 30 and 31 (FIG. 2D). Subsequently, in one embodiment, the envelope motion is again reversed (into the first direction) and the closed envelope 5 is transported to a reception compartment (FIG. 2E).
Another example of a device for closing of envelope flaps is shown in U.S. Pat. No. 3,962,848 issued to Hankins. Hankins discloses an envelope-flap processing apparatus including means for automatically closing flaps. Envelopes travel past a stationary rigid deflector device that deflects and guides a flap into closed position as envelopes are conveyed past the device in the direction of the flap-fold edge.
U.S. Pat. No. 4,499,705 to Russel also discloses an insertion machine including such a mechanism. As particularly shown in FIG. 11, an envelope is moved into the shown position (flap closing station) having its flap 12 closed by abutment finger 154 as the envelope travels (in direction of the flap-fold edge) to this position. Rubber roller 156 is then moved from the side of the envelope over the flap 12 completely to close the flap.
Other envelope-flap closing devices have also been employed. For example, flap closers of a not uncommon kind rely upon the action of rollers onto an envelope (and its flap) that is being conveyed therebetween subsequent to the flap having been guided to an acute angle in relation to its envelope.
As requirements on quality, speed, and economy of processing of mailable articles increase, for example with respect to reliability, throughput rate, and relatively low equipment cost, corresponding demands are also made on flap closing devices. The market demands low equipment-complexity and, at the same time, equipment capability in handling ranges of envelope types, sizes, and thicknesses without a need for adjustment and resetting of mechanisms.
It is desirable that individual machine runs include intermixed thicknesses of envelopes in a broad thickness range, for instance, wherein some envelopes hold one or two inserts (for example checks) and other envelopes hold several tens of inserts. Such greater thicknesses can amount to as much as a large fraction of an inch. Consequently, it is becoming more and more important that flap closing devices also be capable of processing intermixed envelopes in wide ranges of thicknesses without a need for adjustment or resetting.
In general, conventional flap closing devices have not been capable of fulfilling particularly these latter demands while being able to process envelopes at high throughput rates with a high degree of reliability and while being of relatively low complexity and cost.
The rotary flap closer of the present invention is capable of high-speed and reliable processing of envelopes during runs containing intermixed envelopes in a great variety of thicknesses. At the same time, the rotary flap closer of the invention is of relatively low cost and exhibits distinct mechanical simplicity.
Accordingly, an important overall feature of the invention is the provision of an improved envelope-flap closer mechanism and an improved method for closing flaps of envelopes, whereby the mechanism is of low complexity and is capable of reliable, high-throughput rates for batches including relatively broad ranges of intermixed envelope thicknesses without a need for adjustment of the mechanism.